Author round-table 010

Today, we will discuss about Sudoku. The guests this time are Casty and Hone Rokuo. They make a lot of Sudoku which appear on nikoli.com and the mobile site. From Nikoli we have NyanBaz and Nob.

NyanBazWelcome. Actually, these two authors make the most Sudoku, the top two for our site.

Hone RokuoIs that so?

NyanBazSure. And both of you make a lot of puzzles other than Sudoku too.

CastyYes. I don't think that I make particularly many of Sudoku.

Hone RokuoI made only Sudoku recently. Sometimes though, I do make a few of other puzzles. (laughs)

NyanBazIs it easy for you to make Sudoku?

Hone RokuoI was not good at making Sudoku, originally.

NobReally?

Hone RokuoYes. At one time, my work was published a lot in the Pencil Puzzle Books. That made me think that Sudoku was easier to get published than other puzzles. So I started to make more Sudoku.

NyanBazYou said in an interview that getting published motivates you.

Hone RokuoYes. Getting published is important.

NyanBazIn that interview Casty said that Sudoku is the puzzle that takes the most time to make.

CastySure. Sudoku takes the most time.

NyanBazBut Sudoku is not good for making large numbers of puzzles, is it?

Hone RokuoIn the beginning I thought that Sudoku was the kind of puzzle which took a lot of time. But recently, I became fast at it, I got the hang of it so to say. I have a pattern that I follow.

NyanBazBut, Sudoku often doesn't fit into it. You don't always end up with a good problem.

Hone RokuoSure. I but fail less than in the old days. I make the Sudoku as far as I can do it. I am able to understand what will work from the number arrangement or the remaining cells.

NobBut Rokuo makes problems at many levels of difficulty.

Hone RokuoBasically I aim to make medium difficult problems. Then, in the middle of making one, I have to decide if a difficult method is required or not. As a result, it may become an easy or it may become a hard problem. That's why my difficulty levels are all over the chart.

NobHow about you, Casty? You make all kinds of Sudoku from easy to really hard.

CastyWhen I make a hard problem, I make it a hard problem from the beginning.

NobThen, do you fail a lot?

CastySure. (laughs) If I fail, I give it up and I remake it all the way from the beginning.

NyanBazYou remake it from the beginning! Don't you copy it halfway and just remake it from there?

CastyNo I don't really. I make Sudoku thinking ahead before I put in the numbers. When I put a 1 in a cell then next it becomes this and then that, and if necessary I change the 1.

NyanBazWow. It would take a lot of experience to match your skill.

NobIt's important that you should be experienced and used to making Sudoku.

NyanBazSome time ago Rokuo said that you make Sudoku in the range where you could do it. Do you end up making many similar problems?

Hone RokuoYes there is a little bit of that. I can come to like a specific number arrangement. I notice the fun I have by that arrangement suddenly. Then I make some problems with similar arrangements, and I make one more that is similar and it keeps coming. I know that it isn't always good that way.

NobI may make problems in a similar way too. Sudoku is a puzzle where it is hard to get any personality of the author across. Is it only akasyo who can get individual flavors with Sudoku?

NyanBazNow, how about this. Don't you want to put your personal stamp everywhere?

Hone RokuoNo. If I did that I'd fail. (laughs)

CastyMe too.

NobCasty is the same, also with other puzzles. It seems that Casty avoids personality as far as possible.

CastyYes. My motivation lasts long enough not to have to add personality.

Hone RokuoI understand that. I don't get on with it if I insist on adding personality.

NyanBazA new unique idea doesn't pop up all the time. Do you remember when Sudoku became a hit all around the world. Did you feel something when it came into fashion?

Hone RokuoNo nothing whatsoever. When I heard that Sudoku was exploding in the U.K., I thought that the fashion would be over in no time at all. However, Sudoku spread to many more countries, that surprised me. Nowadays Sudoku came to stay throughout the world. I see Sudoku in airports around the world.

NyanBazWhat do you think about that Casty?

CastyI didn't think that the boom would last long either.

NyanBazI was just a reader in those days, but I had the same thought too. (laughs) Nikoli sent Kakuro and Slitherlink and other puzzles out in the world too, but those didn't take root like Sudoku. Where is it that Sudoku is so good?

Hone RokuoHmm, I think it's the plainness of it.

NobThe rules are simple. But it's deep and complex.

Hone RokuoSudoku is just right for a newspaper publication. The moment I see it, I understand what Sudoku is. For example, Nurikabe is incomprehensible at first sight.

NobWriting in numbers may be just right for British newspapers. Because crossword puzzles are also popular in the U.K.

Hone RokuoWell. puzzles where you have to paint in cells wouldn't be understood. To someone who is a beginner with a puzzle, the way of thinking is difficult to catch on to.

NyanBazLet us get back to talking about problem making. Are there things that you would never change with Sudoku?

CastyNot really, I just make Sudoku puzzles naturally like they come.

NyanBazDo you yourself put some sort of limit on the number of expression numbers (the starter numbers)?

CastyNo. I begin to make Sudoku without deciding all the places to put numbers. I add the starter numbers on the way. I generally start up with 22 - 23.

Hone RokuoI see.

NyanBazAnd how many do you end up with?

CastyWhen it's a hard problem, there are generally 24 - 25.

NobThat sounds about right.

CastyI don't pay attention to the number so much. I add numbers if I need to.

NyanBazAre you hung up on how solutions should feel when you are doing a puzzle.

CastyPerhaps yes.

NyanBazHow about you Rokuo? Do you set a limit on starter numbers?

Hone RokuoI stop at 24. In my work there are 22 - 24. I don't enter more than that.

NyanBazIs that just coincidentally?

Hone RokuoNo, I pay attention to that. I don't want to add numbers later. I take care even with the appearance.

NyanBazYou are not very alike here.

Hone RokuoI don't know how to make a problem where there are 30 or 32 starter numbers.

NobI don't understand that either.

Hone RokuoWhen I see a hard problem with that many numbers, and it really is hard, I am impressed, just amazed.

NobSudoku seems to be made in different ways by different people, that also makes it difficult to imitate the ways of other authors.

Hone RokuoI can agree with that. Even if I make a problem in imitation of the number arrangement which another author uses, I'm not successful.

NyanBazIt's mysterious. There isn't any personality in it, but the Sudoku of another author is hard to imitate. I think that the personality is right there, and in Sudoku it is hard to know what personality is.

Hone RokuoAt least it is difficult to put into words.

NyanBazWe will close here today. please give me a message to the solvers.

Hone RokuoSudoku gets only few evaluations and impressions, fewer than other puzzles. If you would leave a comment, that would make me happy.

CastyPlease solve them any way you like. I said a similar thing in the interview. (laughs)

NyanBazThank you for today. Please make a lot of Sudoku problems from now on too.